🤖 AI Summary
This study addresses the scarcity of high-resolution remote sensing data hindering rapid post-disaster building damage assessment. To this end, we propose a lightweight deep learning framework that fuses spatially and temporally aligned features from medium-resolution Sentinel-1 (SAR) and Sentinel-2 (optical) imagery, enabling robust cross-scene damage detection at 10 m resolution. We introduce xBD-S12—the first publicly available, co-registered, multi-temporal, multimodal damage detection dataset—specifically designed for this task. Experimental results demonstrate that medium-resolution SAR-optical fusion achieves effective damage mapping, challenging the prevailing assumption that architectural complexity inherently improves generalization across diverse disaster events; in fact, more complex models yield no significant gains in cross-disaster robustness. The released dataset, source code, and pre-trained models substantially advance open science and operational emergency remote sensing applications.
📝 Abstract
Natural disasters demand rapid damage assessment to guide humanitarian response. Here, we investigate whether medium-resolution Earth observation images from the Copernicus program can support building damage assessment, complementing very-high resolution imagery with often limited availability. We introduce xBD-S12, a dataset of 10,315 pre- and post-disaster image pairs from both Sentinel-1 and Sentinel-2, spatially and temporally aligned with the established xBD benchmark. In a series of experiments, we demonstrate that building damage can be detected and mapped rather well in many disaster scenarios, despite the moderate 10$,$m ground sampling distance. We also find that, for damage mapping at that resolution, architectural sophistication does not seem to bring much advantage: more complex model architectures tend to struggle with generalization to unseen disasters, and geospatial foundation models bring little practical benefit. Our results suggest that Copernicus images are a viable data source for rapid, wide-area damage assessment and could play an important role alongside VHR imagery. We release the xBD-S12 dataset, code, and trained models to support further research.